1. Field of the Invention
The present invention relates to a computer system which shortens the time required for initial loading of files.
2. Description of the Prior Art
FIG. 1 is a block diagram showing a prior art computer system. In FIG. 1, reference numeral 1 is a processor that controls the entire computer system; numeral 2 is a ROM (read only memory) which, for use by the processor 1, contains a program for initial program loading; numeral 3 is a RAM (random access memory) to which the processor 1 loads files needed to be processed; numeral 4 is a disk that acts as an auxiliary memory containing various files including those to be loaded to the RAM 3; and numeral 5 is a disk interface connected to the disk 4.
FIG. 2 is a view illustrating how various files are stored on the disk 4, and FIG. 3 is a view indicating how these files are arranged in hierarchical format. In these figures, reference numerals 10-12 are #1-#3 program files to be loaded to the RAM 3, and numerical 13 is a root directory and #1-#6 directory files defining the hierarchical structure of the program files 10-12.
In operation, applying power to the computer system allows the processor 1 to execute the program stored in the ROM 2. In this example, the program in the ROM 2 loads the #1 program file 10 through #3 program file 12 to the RAM 3.
The root directory 13 is read from the disk 4, the contents of the directory being analyzed to find the location where the #1 directory file 14 is stored. The #1 directory file 14 is read from the location thus acquired. In turn, the contents of the file 14 are analyzed to find the location where the #1 program file 10 to be loaded is stored. From the location thus obtained, the #1 program file 10 is read and loaded to the RAM 3 via the disk interface 5.
When the loading of the #1 program file 10 is completed, the root directory 13 is again read in order to load the #2 program file 11. In the same manner, subsequent files in the hierarchical structure are successively traced, from the #2 directory file 15 to #3 directory file 16 and so on, until the location where the #2 program file 11 is acquired. When read out, the #2 program file 11 is loaded to the RAM 3. In this case, because the #2 program file 11 is hierarchically lower than the #1 program file 10, the disk 4 needs to be accessed more often than in the case of the #1 program file in order to find the location where the #2 program file 11 is stored.
Since the #3 program file 12 is still lower in the file hierarchy, the four directory files, from the root directory 13 to #4-#6 directory files 17-19, are read out, their contents being analyzed to acquire the location where the #3 program file 12 is stored. From that location the #3 program file 12 is read and loaded to the RAM 3.
Because the prior art computer system is typically constructed as outlined above, one problem therewith is that the disk 4 needs to be accessed a very large number of times in order to load the object file to the RAM 3. The prolonged loading time means that the computer system must remain functionally idle for the duration of that time, i.e., between the time it is powered up and the time it is ready for use.